This invention relates generally to connectors for optical fiber transmission lines comprising only a single mode fiber.
If fiber optic cables are to be used in practical signal transmission and processing systems, practical connectors for the connection and disconnection of fiber optic cables must be provided. The difficulty in achieving connections between single fibers which are sensitive to axial misalignment problems has created an obstacle to the use of long run single data transmission systems.
In the case of a single fiber transmission line, the alignment between the ends of the two fibers requires extreme precision due to the very small dimensions of their respective cross sections. Various factors including the separation distance and axial misalignment affect the light transfer efficiency of a connector.
There are several mechanical methods of connecting optical fibers but all do not readily provide sufficient accuracy for joining and aligning small diameter single mode fibers.
Once such device is U.S. Pat. No. 3,734,594. This connector uses a deformable annular core having pressure plates at both ends. The fiber ends are inserted into the core and a force is applied on the plates to deform the core to align and secure the fibers.
Another device for connecting fibers is U.S. Pat. No. 4,142,777 which consists of three strategically placed cylindrical rods to allow a channel between them for a optical fiber to pass and be aligned.
Still another connector is U.S. Pat. No. 4,057,322 depicting an apparatus for forming reference planes which connect with support structures to assure alignment of the optical fiber.
A major factor of any connecting device is to be an efficient coupling device when it is disconnected and connected during the course of use without substantial losses. What is needed, as described in the present invention, is a device that can be disconnected and connected yet obtain minimum loss by a slight adjustment to axially align the optical fibers, and hence provide minimum losses.
All of the previous connectors also suffer from problems in manufacturing because the inability to provide accurate tolerances yield parts which, in turn, give unsatisfactory connector performance. The device according to the present invention remedies the above mentioned drawbacks and provides improved performance with respect to the prior art.
The novel features which are belived to be characteristics of the invention, both as to its organization and its method of operation, together with further objects and advantages thereof, will be better understood from the following description in connection with the accompanying drawings in which a presently preferred embodiment of the invention is illustrated by way of example. It is expressly understood, however, that the drawings are for purposes of illustration and description only, and are not intended as a definition of the limits of the invention.